1. Field of the Invention
The present invention relates to industrial vehicles, such as lift trucks; and more particularly monitoring and managing the operation of the industrial vehicles.
2. Description of the Related Art
Material handling vehicles are powered vehicles commonly used in a facility, such as warehouse, a factory or a store, to transport materials and finished goods. A human operator either sits on a seat or stands on a platform of the vehicle and manipulates controls which govern movement through the facility and operation of a load carrier on which items being transported are placed. Examples of material handling vehicles include, but are not limited to, fork lift trucks, order pickers, stand-up counterbalanced lift trucks, sit-down counterbalanced lift trucks, lift trucks and tow tractors.
Another type of industrial vehicle, known as an autonomously guided vehicle (AGV), is a form of mobile robot that transports goods and materials from one place to another in a constrained environment, such as a factory or a warehouse. Some AGV's followed a wire buried in the floor and thus were limited to traveling along a fixed path defined by that wire. More sophisticated guidance technology developed so that the vehicle was not confined to a fixed path.
In warehousing operations, material quantities and inventory turnover rates are increasing rapidly. Therefore, to maintain competitiveness, it is important to have accurate information about inventory, and to ensure that each piece of equipment, and each employee is productive. For a warehouse to compete on the global level, continually improving operator productivity is vital to reducing costs. To meet these ends, facility management systems are frequently employed to control inventory, ensure proper maintenance of equipment, and to monitor operator efficiency. In these facility management systems, a centralized computer system is used to monitor inventory flow, maintenance status of fleets of industrial vehicles, and operator performance parameters.
To gather data for the monitoring functions, sensors connected by a wiring harness to a data collection computer are frequently added to a material handling vehicle after manufacture. Running the wiring harness throughout the vehicle is time consuming and expensive because of the number of connection points. It is desirable to provide an alternative technique that enables communication between the sensors and either the standard controller already onboard the material handling vehicle or a new dedicated data collection computer. Other techniques to simplify retrofitting sensors and control systems to material handling vehicles also are desired.
It is advantageous that the performance data regarding the material handling vehicles and their operators be transferred to central computer system in the facility. This permits the performance information to be analyzed and compared with similar data from other vehicles and operators. Such analysis is used to determine when a particular vehicle requires maintenance and whether a greater or lesser number of vehicles is required for optimal operating efficiency of the warehouse or factory.
Previously, each material handling vehicle included a wireless transceiver for exchanging data and commands with the facility management system. That system had a local area communication network connected to a plurality of wireless transceivers located throughout the facility. The network transceivers were located so that no matter where a material handling vehicle traveled, it always was within communication range of a network transceiver. Such a local area communication network was relatively expensive and sometimes too costly for small facilities or those with only a few vehicles.
Only persons who have received training are allowed to operate the material handling vehicles. Further the operation of different types of such vehicles requires separate training. Therefore, only those persons trained to operate a particular type of material handling vehicle are permitted to do so. Although a person may have received basic training for a material handling vehicle, his or her operation may be limited until a level of experience has been acquired. For example, until a person has operated a vehicle for a specified number of hours the speed at which his/her vehicle may travel or certain other function may be limited. It is desirable to provide a mechanism that prevents unauthorized persons from operating these vehicles.